Atomic Layer Deposition of La2O3 Film with Precursor La(thd)3-DMEA

Abstract

In this paper, a new precursor La(thd)3-DMEA (thd = 2,2,6,6-tetramethyl-3,5-heptanedione, DMEA = N,N′-dimethylethylenediamine) was synthesized and characterized with 1H-NMR and X-ray single crystal diffraction. The thermal properties of La(thd)3-DMEA were checked by thermogravimetric analysis (TGA), which confirmed that the volatility and suitability of La(thd)3-DMEA are suitable for atomic layer deposition (ALD). We studied the atomic layer deposition of La2O3 films on a SiO2 surface with La(thd)3-DMEA and O3 as precursors. Self-limiting deposition behaviors were found for the prepared films. The purity and surface morphology of the as-grown La2O3 films, which possessed a constant growth rate of ~0.4 Å/cycle at 250–280 °C, were confirmed by XPS, SEM, and AFM. The results show that La(thd)3-DMEA is a suitable precursor for the atomic layer deposition of La2O3 film.

Atomic Layer Deposition of CeO2 Film with a Novel Heteroleptic Ce(III) Complex

“…The average length of Ce-O bonds from the chelate thd − ligand was 2.427 Å, which was not significantly different from the 2.472 Å found in [Ce 2 (etbd) 6 (tetraglyme)] [47]. The average Ce-O (thd) and Ce-N (MEDA) bond lengths compare well with that found in the lanthanum [48] and are in good agreement with the value expected for a Ce III ion. The observed bond length trend agrees well with the ionic radii variation from Ce III (1.11 Å) through to La III (1.15 Å) [50].…”

“…In our previous study, La(thd) 3 -DMEA (DMEA = N, N ′ -dimethylethylenediamine) as a heteroleptic complex was synthesized and used as an ALD precursor to deposit La 2 O 3 film. It showed that the introduced neutral ligands saturated the metal center and improved volatility and thermal stability [48]. Leskelae T, et al synthesized Ce(thd) 3 -phen (phen = 1, 10-phenanthroline) with a high melting point (210 • C) as a heteroleptic ALE precursor, which was sublimated in two stages, indicating phen of the adduct molecules during the sublimation and the complexing ability of the oxygen β-diketonate ligand with a cerium ion was stronger than that of a nitrogencontaining bidentate heterocyclic neutral ligand [49].…”